The present invention relates generally to devices for location in an ear canal, and more particularly to earplugs that are insertable, self-conforming and used for noise reduction, e.g., sound attenuation.
The need for adequate hearing protection in noisy environments has long been recognized among those concerned with health and safety issues, and much effort has gone into providing such protection. However, most experts in this field would acknowledge that this effort has not been completely successful. Protective devices have proliferated yet remain needing in performance, particularly in terms of a comfortable fit over a longer period of time (e.g., at least 4 hours). Workers in noisy environments who should use these devices often do not, or use them only under duress from their employers, and then do so improperly because they value comfort over a proper, likely uncomfortable, fit. Individuals that work in noisy environments rarely understand that the effects of noise exposure are not limited to the moment but are cumulative as well. The lack of worker compliance with safety rules is exacerbated by the fact that currently available hearing protection devices are often uncomfortable, clumsy to use, and/or perform less than optimal due to improper insertion in the ear canal. Additionally, human ear canal sizes vary from about 7 to about 8 millimeters in diameter for “small” canals, to about 9 to about 10 millimeters in diameter for “medium” canals, to about 11 to about 12 and as much as about 14 millimeters for “large” canals. Fortunately, as hearing protection devices become more comfortable and/or fit better across a broader range of canal sizes, worker compliance with their use should also improve.
For example, existing disposable roll-down foam earplugs can be uncomfortable when worn over longer periods of time, are difficult to properly insert, and/or do not readily stay in place for a longer period of time. Common disposable foam earplugs require the user to compress the volume of the plug and insert it into the ear canal where it then attempts to re-expand. This method can cause discomfort for people with ear canals that are not the largest ones contemplated for that earplug's intended use, in that the more compressed the earplug in an ear sized smaller than “large”, the greater the earplug's exerted outward force toward re-expansion. Such a roll-down type earplug may be found, for example, in U.S. Pat. No. 6,105,715 to Knauer.
Further, existing disposable foam earplugs require the user to roll the foam between their fingers to compress the foam to a sufficient size for proper insertion. If this step is not done, or is done insufficiently, the earplug is often inserted improperly (i.e., usually meaning not inserted enough into the ear canal) so as to not provide optimal protection (i.e., not optimal often being as little as 25% of the earplugs' advertised Noise Reduction Rating (“NRR”) as determined by industry standards). And, even when the earplug is initially inserted properly, it is common for workers in a work environment that requires continuous earplug use to experience discomfort from the pressure exerted from the residual expansion forces of the rolled earplug. The discomfort is sometimes relieved by the partial removal of the earplug from the ear canal, thereby compromising the sound attenuating protection of the device. Also, if the user has dirty hands when compressing the earplug, dirt and/or germs are then put into the ear canal with the inserted earplug.
As with roll-down type earplugs, push-in type earplugs attenuate sound by causing an occlusion within the car canal, thus obstructing the passage of sound therethrough. Push-in type earplugs generally comprise an attenuating annular portion and a rigid to semi-rigid stem portion typically extending therefrom or embedded therein and used as an insertion means. The sound attenuating portion is typically of a soft compressible material. The rigid to semi-rigid portion may be composed of any material with sufficient rigidity as required to overcome the insertion pressure of the earplug, and is often formed of the same material in one molding process step. To insert the push-in type earplug, the user grasps the rigid/semi-rigid portion (or an end of the earplug proximate thereto), positions the earplug proximate the ear canal opening, and inserts the sound attenuating portion into the canal by pushing with the rigid/semi-rigid portion. The sound attenuating portion compresses, as necessary, upon entry into the ear canal and is held therein by a friction fit, occluding the canal and providing sound attenuation. Such a push-in type earplug may be found, for example, in U.S. Pat. Nos. 4,867,149 and 5,188,123 to Falco and Gardner Jr., respectively.
Push-in type earplugs are considered by many to provide easier insertion than other types of plugs. As discussed above, the wearer simply grasps the rigid or semi-rigid portion (or the end of the earplug proximate thereto) and inserts the sound attenuating portion at the opposite end into the car canal, lodging the earplug therein and, hence, occluding the canal. However, while allowing a simplistic insertion, the push-in type ear plug typically does not yield the higher attenuations often provided by roll-down type earplugs. This may be because the push-in plug typically has a less surface area contacting the ear canal when inserted therein, or perhaps because the push-in plug wrinkles or folds during insertion creating leaks, or further, because the push-in plug does not stay firmly in place during use and backs slightly out of the ear canal.
Therefore, existing roll-down and push-in type earplug materials and constructions alone do not have the ability to simultaneously accommodate each of: adequate insertion means, comfortable fit and sound attenuation. Accordingly, a hearing protection device is needed which is easy to insert, comfortable to the user during a longer period of use, and provides desired sound attenuation. The applicants have surprisingly invented such a device, as discussed further herein.